Substrate characterized by including methylhydrosiloxane composition film or methylhydrosiloxazane composition film, in which silica fine particles are dispersed, and method for producing same

Abstract

Provided is a substrate (10) that comprises a methylhydrosiloxane composition or a film (12) composed of a methylhydrosiloxazane composition, in which silica fine particles are dispersed as a matrix material.

Description

Substrate characterized by comprising a methylhydrosiloxane composition film or a methylhydrosiloxazane composition film in which silica fine particles are dispersed, and a method for manufacturing the same

[0001] The present invention relates to a substrate comprising a methylhydrosiloxane composition film or a methylhydrosiloxazane composition film in which silica fine particles are dispersed, and a method for producing the same.

[0002] There is a need for a technology for filling and planarizing grooves (steps) formed in a substrate with a silica film that is stable and highly productive without causing cracks or peeling. Generally, in semiconductors, liquid crystal panels, and the like, elements, wiring, and the like are stacked from bottom to top on a single semiconductor wafer or glass substrate. Therefore, it is necessary to planarize protrusions and steps due to elements, wiring, and the like in order to facilitate the formation of upper layers and reduce misalignment in the plane direction during lithography. In particular, due to recent demands for higher integration and higher definition in semiconductor chips, liquid crystal panels, and the like, the height (depth) of these protrusions and steps tends to increase, sometimes reaching 1 μm or more, making filling and planarization thereof increasingly important.

[0003] Furthermore, when manufacturing semiconductor devices using the so-called chip-on-wafer method, which is formed by stacking multiple chips of the same type or different types such as CPUs and memories, which are attracting attention as next-generation semiconductors, it is necessary to mount cut chips on a base wafer, fix the chips, and then fill the grooves between adjacent chips. In this case, the depth of the grooves is usually 10 μm or more, and a film that can fill and flatten the grooves is required.

[0004] A siliceous coating composition used for purposes such as stress relaxation, improving hardness and heat resistance, and imparting thixotropy has been disclosed (Patent Document 1). The siliceous coating composition includes a matrix member that holds siliceous fine particles in a dispersed state. The carbon content of the siliceous fine particles and the siliceous coating composition is set to 5 wt % or less.

[0005] Furthermore, a technique for providing a trench-filling composition suitable for use in filling a trench formed in a substrate with silicon oxide, which provides a silicon oxide coating film with high trench-filling properties, small cure shrinkage, and good crack resistance, has been disclosed (Patent Document 2). This technique discloses a trench-filling composition containing a hydrogenated polysilazane compound and a reactant having a structure derived from silica particles.

[0006] JP 2019-182893 A JP 2010-177647 A

[0007] Chemical vapor deposition (CVD) is also known as a technique for forming such films. However, since chemical vapor deposition (CVD) forms a film conforming to the shape of the substrate, it is not suitable for filling grooves or flattening the surface. Furthermore, the film formation speed is slow and productivity is poor.

[0008] Furthermore, when a sol-gel liquid or a siloxane compound containing a bulky organic group such as an ethyl group is used as a matrix material, the volume shrinkage is large because the curing is accompanied by a dehydration reaction during silica conversion, and when a thick film of 0.5 μm or more is formed, cracks and peeling are likely to occur, making it difficult to ensure stability and productivity.

[0009] Furthermore, when polyimide or the like is used as a heat-resistant organic resin, shape control is difficult due to the large thermal changes, such as expansion and contraction, compared to silica-based materials. Furthermore, manufacturing is difficult due to the decomposition and elution of organic components during the etching and cleaning processes.

[0010] Furthermore, the technology described in the above prior art documents uses a polymer containing no organic groups, such as hydrogenated polysilazane, as a matrix material, and therefore forms an inorganic silica material that contains essentially no or only a small amount of carbon components after heating and curing. Therefore, while it has the advantage of being able to form a high-hardness, high-strength film, it has the disadvantage of being prone to cracking and peeling due to bending or thermal changes during and after production, resulting in high stress during heating and curing. This disadvantage is more pronounced when using a substrate with unevenness, even when using a substrate with even greater unevenness, than when using a flat substrate. Furthermore, due to its low solubility in solvents and high reactivity with water, it is difficult to uniformly mix with siliceous microparticles, resulting in problems with the storage stability of the mixed solution.

[0011] One aspect of the present invention is a substrate comprising a film in which silica particles are dispersed in a matrix material of a methylhydrosiloxane composition or a methylhydrosiloxazane composition.

[0012] Here, it is preferable that the substrate has a step of 1 μm or more, and the film is buried 1 μm or more from the bottom of the step.

[0013] It is also preferable that the average carbon content of the film is 8 wt % or more and 18 wt % or less.

[0014] The silica fine particles preferably have an average primary particle size of 5 nm or more and 150 nm or less.

[0015] Another aspect of the present invention is a method for manufacturing a substrate, which comprises applying to a substrate a material in which silica fine particles are dispersed in a matrix material of polymethylhydrosilazane or polymethylhydrosiloxazane having a weight-average molecular weight of 400 to 20,000, and then heating the material.

[0016] The silica fine particles preferably have an average primary particle size of 5 nm or more and 150 nm or less.

[0017] It is also preferable that the mixing ratio (weight ratio) of the silica fine particles to the matrix material is 3 wt % or more and 200 wt % or less.

[0018] It is also preferable that the ratio of Si--H bond / Si--Me bond in the structure of the matrix material is 0.3 or more and 0.9 or less, and the ratio of N--H bond / Si--Me bond is 0.4 or more and 1.1 or less.

[0019] According to the present invention, it is possible to provide a film-coated substrate on which a film that does not crack or peel off is formed, particularly a film-coated substrate on which a film that does not crack or peel off even when the film has a thickness of 1 μm or more is formed.

[0020] Fig. 1 is a cross-sectional view illustrating a structure of a film-coated substrate according to an embodiment of the present invention. Fig. 2 is a cross-sectional view illustrating a structure of a film-coated substrate according to an embodiment of the present invention. Fig. 3 is a cross-sectional view illustrating a structure of a film-coated substrate according to an embodiment of the present invention. Fig. 4 is a cross-sectional view illustrating a structure of a film-coated substrate according to an embodiment of the present invention. Fig. 5 is a cross-sectional view illustrating a structure of a film-coated substrate according to an embodiment of the present invention. Fig. 6 is a diagram illustrating a composition change of a matrix material according to an embodiment of the present invention.

[0021] [Configuration of Substrate] As shown in FIG. 1, a film-coated substrate 100 according to an embodiment of the present invention is configured by laminating a substrate 10 and a film 12 .

[0022] The substrate 10 is a member on whose surface a film 12 is formed. The substrate 10 is not particularly limited, but may be, for example, a semiconductor substrate. The substrate 10 may be, for example, a semiconductor substrate on which elements constituting an electric circuit, such as transistors and capacitors, are formed, or a substrate on which a color filter of a liquid crystal panel is formed.

[0023] The film 12 is formed on the surface of the substrate 10. The film 12 is used as an insulating film, a buried layer, a planarizing film, a passivation film, or the like in the substrate 10 for a semiconductor, a liquid crystal panel, or the like. Specifically, the film 12 is used, for example, as an insulating film, a planarizing film, or a buried film for elements constituting an electric circuit such as a transistor or a capacitor, wiring, or a structure constituting a circuit. The film 12 is also used to fix upper and lower layers when stacking semiconductor chips themselves, and as a buried layer or a planarizing film for grooves formed between chips when an upper chip is placed. The film 12 is also used, for example, as a buried layer or a planarizing film for uneven portions of color filters of a liquid crystal panel, or the like. The film 12 is also used, for example, as a passivation film (barrier film) that blocks moisture or oxygen that oxidize and deteriorate electric circuits and electric elements.

[0024] The film 12 is made of a material in which silica particles are dispersed in a matrix material of a methylhydrosiloxane composition or a methylhydrosiloxazane composition. The methylhydrosiloxane composition has a backbone of Si—O bonds, and the methylhydrosiloxazane composition has a backbone of Si—O bonds and partially Si—N bonds, and is formed of H—Si—Me (where Me is a methyl group CH ３ ) bond.

[0025] The reasons for selecting a methylhydrosiloxane composition or a methylhydrosiloxazane composition as the matrix material include: (1) it has a Si—O bond framework similar to that of the silica microparticles and the silicon or glass substrate 10; (2) the Si—Me bond can provide the film 12 with the function of achieving both strength and flexibility; and (3) the Si—H bond increases the reactivity with the silica microparticles and the Si—OH bond on the surface of the substrate 10, thereby increasing the adhesion between the silica microparticles and the substrate 10.

[0026] As the material for forming the methylhydrosiloxane or methylhydrosiloxazane matrix material, it is preferable to use polymethylhydrosilazane or polymethylhydrosiloxazane having a weight-average molecular weight of 400 to 20,000. If the weight-average molecular weight is less than 400, the material may flow when mixed and dispersed with silica microparticles in an organic solvent and applied to the substrate, failing to be fixed to the surface of the substrate 10, or may evaporate during heating, making it difficult to form a homogeneous film 12. Furthermore, if the weight-average molecular weight exceeds 20,000, the material may be difficult to dissolve in an organic solvent when mixed and dispersed with silica microparticles.

[0027] Furthermore, the Si—H bond / Si—Me bond ratio of polymethylhydrosilazane or polymethylhydrosiloxazane, which is the material forming the methylhydrosiloxane composition or methylhydrosiloxazane composition that is the matrix material, is preferably within the range of 0.3 to 0.9. Similarly, the N—H bond / Si—Me bond ratio in polymethylhydrosilazane or polymethylhydrosiloxazane is preferably within the range of 0.4 to 1.1. If the Si—H bond / Si—Me bond ratio is less than 0.3 or if the N—H bond / Si—Me bond ratio is less than 0.4, when the organic solvent mixed and dispersed with silica microparticles is applied to substrate 10, adhesion to substrate 10 and silica microparticles is reduced, and cracks or peeling may occur in film 12 after heating. Furthermore, if the ratio of Si—H bonds / Si—Me bonds exceeds 0.9, or if the ratio of N—H bonds / Si—Me bonds exceeds 1.1, problems arise such as an increase in viscosity when mixed and dispersed with silica fine particles in an organic solvent, or a decrease in the storage stability of the solution after mixing and dispersion.

[0028] The film 12 preferably contains dispersed silica particles. Examples of silica particles that can be used include colloidal silica, fused silica, fumed silica, and silica produced by sintering and crushing or vaporization combustion. Surface-treated silica particles with a silane coupling agent or the like can also be used to enhance dispersibility in organic solvents. The silica particles preferably have a primary particle size (average diameter) of 5 nm to 150 nm. If the primary particle size (average diameter) of the silica particles is less than 5 nm, problems such as aggregation can occur, such as inability to disperse in organic solvents or inability to mix homogeneously with polymethylhydrosilazane or polymethylhydrosiloxazane. Furthermore, if the primary particle size (average diameter) of the silica particles exceeds 150 nm, problems such as inability to stably disperse and retain in organic solvents due to sedimentation can occur. Furthermore, when applied to devices such as liquid crystal panels, the transparency of the film 12 can be enhanced in the visible light range by setting the primary particle size (average diameter) of the silica particles to 5 nm to 150 nm.

[0029] The mixing ratio (weight ratio) of silica fine particles to polymethylhydrosilazane or polymethylhydrosiloxazane, which are materials forming the methylhydrosiloxane or methylhydrosiloxazane matrix material, is preferably within the range of 3 wt % to 200 wt %. If the mixing ratio (weight ratio) is less than 3 wt %, problems such as flow when applied to the substrate 10 and failure to fix to the substrate 10, or cracks forming in the film 12 after heating, may occur. If the mixing ratio (weight ratio) exceeds 200 wt %, the spaces between the fine particles may not be completely filled when applied to the substrate 10, resulting in only the fine particles being exposed from the film 12, or roughness may occur in the film 12, making it difficult to form a homogeneous film 12.

[0030] The average carbon content, which indicates the mixing ratio of silica microparticles to the methylhydrosiloxane or methylhydrosiloxazane matrix material, is preferably 8 wt% or more and 18 wt% or less. If the average carbon content is less than 8 wt%, there is a high risk of cracking or peeling in the formed film 12. Furthermore, if the average carbon content exceeds 18 wt%, there is a risk that the strength of the formed film 12 will decrease or that shrinkage during the film 12 formation process will increase, making it difficult to control the shape of the film 12.

[0031] FIG. 2 shows a schematic cross-sectional view of a substrate 10 having a stepped surface on which a film 12 is embedded, the film 12 having silica particles dispersed in a matrix material of methylhydrosiloxane or methylhydrosiloxazane.

[0032] 2(a) to 2(c) show three cases showing the relationship between the height (depth) H1 of the step in the substrate 10 and the film thickness H2 of the film 12 filled in the step. FIG. 2(a) shows a case where the film thickness H2 of the film 12 filled in the step is smaller than the height (depth) H1 of the step in the substrate 10. FIG. 2(b) shows a case where the height (depth) H1 of the step in the substrate 10 is equal to the film thickness H2 of the film 12 filled in the step. FIG. 2(c) shows a case where the film thickness H2 of the film 12 filled in the step is larger than the height (depth) H1 of the step in the substrate 10.

[0033] 2(a) to 2(c), no cracks or peeling occurred in the film 12 after formation, and a stable film 12 could be formed. In particular, even when the height (depth) H1 of the step provided on the substrate 10 was 1 μm or more and the film thickness H2 of the film 12 embedded in the step was 1 μm or more, no cracks or peeling occurred. In other words, according to this embodiment, even when the film thickness of the film 12 was 1 μm or more, no cracks or peeling occurred, and a stable film 12 could be formed.

[0034] 3, after the step is filled, the film outside the step can be polished and removed by a method such as CMP to flatten the entire substrate. In this case, it is preferable to form the film 12 so that the film thickness H2 of the film 12 filled in the step is equal to the height of the step (FIG. 2(b)), or to form the film 12 so that the film thickness H2 of the film 12 filled in the step is greater than the height of the step (FIG. 2(c)).

[0035] Furthermore, when an organic solvent containing polymethylhydrosilazane or polymethylhydrosiloxazane with dispersed silica microparticles is applied to substrate 10 by a method in which the solvent is evaporated and fixed, such as spin coating, spray coating, slit coating, gravure coating, or roll coating, the coating liquid essentially flows down from the top of the step to the inside of the step. As a result, as shown in Figure 4, the film thickness T2 inside the step tends to be larger than the maximum film thickness t1 outside the step on substrate 10, sufficiently distant from the step. Furthermore, the film thicknesses t1 to t4 of film 12 in the peripheral portion outside the step on substrate 10 tend to decrease as they approach the step.

[0036] Here, the pattern provided on the surface of the substrate 10 is not particularly limited in shape, arrangement, or position. For example, the pattern can be a line-shaped, circular, rectangular, or other hole. The effect of the film 12 is particularly pronounced when the height (depth) H1 of the pattern step is 1 μm or more. The width of the pattern is not particularly limited, but considering the size of the silica microparticles dispersed in the film 12, it is preferable that the minimum width be 30 nm or more. On the other hand, depending on the application, the pattern width may be 1 μm or more, or even 1 mm or more. Furthermore, the sidewalls of the step do not need to be vertical, and may be tapered or inversely tapered.

[0037] [Manufacturing Method] In the present embodiment, film 12 is formed by first applying an organic solvent in which silica particles are mixed and dispersed in polymethylhydrosilazane or polymethylhydrosiloxazane to the surface of substrate 10, then scattering and fixing the organic solvent, and then heating the resulting film to oxidize the polymethylhydrosilazane or polymethylhydrosiloxazane and convert it into a methylhydrosiloxane composition or a methylhydrosiloxazane composition.

[0038] The weight-average molecular weight of the polymethylhydrosilazane or polymethylhydrosiloxazane is preferably 400 to 20,000. The average primary particle size of the dispersed silica microparticles is preferably 5 to 150 nm. The mixing ratio (weight ratio) of the silica microparticles to the polymethylhydrosilazane or polymethylhydrosiloxazane is preferably 3 to 200 wt %.

[0039] The ratio of Si—H bonds to Si—Me bonds in the polymethylhydrosilazane or polymethylhydrosiloxazane is preferably in the range of 0.3 to 0.9, and the ratio of N—H bonds to Si—Me bonds in the polymethylhydrosilazane or polymethylhydrosiloxazane is preferably in the range of 0.4 to 1.1.

[0040] Polymethylhydrosilazane or polymethylhydrosiloxazane has the property of reacting with moisture and polymerizing. Therefore, if these organic solvents contain moisture, the resulting polymer may become too high molecular weight or gel, which may cause problems such as changes in the film thickness of the film 12 or difficulty in application. Therefore, it is preferable to keep the moisture content in the organic solvent to 1 wt % or less.

[0041] The organic solvent is preferably a single or multiple solvents selected from aromatic hydrocarbons such as toluene, xylene, and trimethylbenzene; saturated hydrocarbons such as hexane, hexene, and octane; ethers such as butyl ether, amyl ether, and anisole; esters such as ethyl acetate, propyl acetate, and butyl acetate; and ketones such as diethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0042] The organic solvent containing polymethylhydrosilazane or polymethylhydrosiloxazane in which silica fine particles are dispersed can be applied to the substrate 10 by a method in which the solvent is vaporized and fixed, such as spin coating, spray coating, slit coating, gravure coating, or roll coating, but the application method is not limited to these.

[0043] Furthermore, when filling deep grooves or steps of several micrometers or more, a thick film can be formed by applying a mixture of polymethylhydrosiloxane or polymethylhydrosiloxazane and silica fine particles to a substrate, dispersing the organic solvent to allow the mixture to set, and then heating the substrate. While it is possible to form a film of several micrometers or more at a time, this requires increasing the viscosity of the coating solution, which can prevent difficulties in handling the coating solution and coating equipment.

[0044] An organic solvent containing polymethylhydrosilazane or polymethylhydrosiloxazane with dispersed silica microparticles is applied to the substrate 10, the organic solvent is evaporated to allow the coating to set, and then a heat treatment is performed. The heating method is not particularly limited, but an oven or a hot plate can be used, for example. The heating temperature is preferably 150°C or higher and 600°C or lower. The heating atmosphere is preferably an oxidizing gas such as air, oxygen, or water vapor. Dry nitrogen, argon, or the like may also be used as a balance gas.

[0045] FIG. 5 shows the estimated structural changes of the matrix portion before and after heating. In FIG. 5, a, b, c, k, and x, y, and z are present randomly. Before heating, the matrix is ​​composed of a, b, and c in the case of polymethylhydrosilazane, and a, b, c, and k in the case of polymethylhydrosiloxazane. Here, the compositional ratios of a, b, c, and k are a: a 5% to 70%, b 10% to 60%, c 3% to 20%, and k 0% to 15%. After heating, some or all of the Si—N bonds are oxidized, and the matrix is ​​composed of x and y in the case of a methylhydrosiloxane composition, and x, y, and z in the case of a methylhydrosiloxazane composition. Here, the compositional ratios of x, y, and z are x 1% to 20%, y 70% to 100%, and z 0% to 20%. The compositional ratios are combined so that there is no contradiction in each combination. For example, when y is 100%, the other x and z are set to 0%.

[0046] [Example] [Synthesis of Polymethylhydrosilazane A] A 2-L stainless steel autoclave was equipped with a stirrer, nozzles for injecting and discharging chemicals or gases into the liquid and gas phases, and a cooling and control device for controlling the temperature of the contents. After thoroughly drying the interior of the autoclave using dry nitrogen, 300 g of toluene and 300 g of pyridine that had been dehydrated using molecular sieves were poured into the autoclave and cooled to 0°C with stirring. 50 g of methylhydrodichlorosilane was gradually poured into the autoclave, and 50 g of dry ammonia was poured over 2 hours while maintaining the temperature at 0°C. After injecting dry nitrogen to remove excess ammonia, the reaction solution was filtered through a SUS316 filter with a filtration accuracy of 25 μm. The resulting filtrate was mixed with 500 g of toluene that had been dried using molecular sieves, and the mixture was distilled in a rotary evaporator at a bath temperature of 50°C until the contents reached approximately 200 g. This was mixed with 200 g of dried toluene, and the solvent was thoroughly distilled off using a rotary evaporator also at a bath temperature of 50° C., yielding about 15 g of a viscous liquid.

[0047] The resulting viscous liquid was subjected to H-NMR (400 MHz) measurement using CDCl as a lock solvent. A peak at 0.1 to 0.2 ppm attributable to Si-Me bonds, a peak at 0.4 to 1.8 ppm attributable to N-H bonds, and a peak at 4.1 to 5.1 ppm attributable to Si-H bonds were observed. Based on the integral ratio of each peak (based on the number of protons), the ratio of Si-H bonds / Si-Me bonds was 0.82, and the ratio of N-H bonds / Si-Me bonds was 0.75.

[0048] The viscous liquid was applied to a KBr plate, and the FTIR spectrum was measured using an FTIR device (manufactured by Jasco: Model FT / IR-4100). The FTIR spectrum showed peaks at 1,180 and 3,370 cm assigned to the N—H bond. －１ absorption at 1,260 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ The absorption was observed.

[0049] Furthermore, when the viscous liquid was measured by GPC, it was found that the weight average molecular weight was 850 in terms of polystyrene.

[0050] From the above analysis results, the obtained viscous liquid was identified as polymethylhydrosilazane.

[0051] [Synthesis of Polymethylhydrosilazane B] A 2-L stainless steel autoclave was equipped with a stirrer, nozzles for injecting and discharging chemicals or gases into the liquid and gas phases, and a cooling and control device for controlling the temperature of the contents. After thoroughly drying the autoclave with dry nitrogen, 300 g of toluene and 300 g of pyridine dehydrated with molecular sieves were poured into the autoclave and cooled to 0°C with stirring. 20 g of methylhydrodichlorosilane and 30 g of methyltrichlorosilane were gradually poured into the autoclave, and 50 g of dry ammonia was poured over 2 hours while maintaining the temperature at 0°C. After injecting dry nitrogen to remove excess ammonia, the reaction solution was filtered through a SUS316 filter with a filtration accuracy of 25 μm. The resulting filtrate was mixed with 500 g of toluene dried with molecular sieves, and the mixture was distilled in a rotary evaporator at a bath temperature of 50°C until the contents reached approximately 200 g. This was mixed with 200 g of dried toluene, and the solvent was thoroughly distilled off using a rotary evaporator also at a bath temperature of 50° C., yielding about 18 g of a viscous liquid.

[0052] The resulting viscous liquid was subjected to H-NMR (400 MHz) measurement using CDCl as a lock solvent. A peak at 0.1 to 0.2 ppm attributable to Si-Me bonds, a peak at 0.4 to 1.8 ppm attributable to N-H bonds, and a peak at 4.1 to 5.1 ppm attributable to Si-H bonds were observed. Based on the integral ratio of each peak (based on the number of protons), the ratio of Si-H bonds / Si-Me bonds was 0.39, and the ratio of N-H bonds / Si-Me bonds was 1.05.

[0053] The viscous liquid was applied to a KBr plate, and the FTIR spectrum was measured using an FTIR device (manufactured by Jasco: Model FT / IR-4100). The FTIR spectrum showed peaks at 1,180 and 3,370 cm assigned to the N—H bond. －１ absorption at 1,260 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ The absorption was observed.

[0054] Furthermore, when the viscous liquid was measured by GPC, the weight average molecular weight in terms of polystyrene was found to be 1,800.

[0055] From the above analysis results, the obtained viscous liquid was identified as polymethylhydrosilazane.

[0056] [Synthesis of Polymethylhydrosiloxazane C] A 2L stainless steel autoclave was equipped with a stirrer, nozzles for injecting and discharging chemicals or gases into the liquid and gas phases, and a cooling and control device for controlling the temperature of the contents. After thoroughly drying the autoclave with dry nitrogen, 50 g of pyridine dehydrated with a molecular sieve was poured in and cooled to 0°C while stirring. A solution of 12 g of the polymethylhydrosilazane A obtained above dissolved in 90 g of toluene dehydrated with a molecular sieve was gradually poured into the autoclave. Next, 40 g of pyridine dehydrated with a molecular sieve and 0.5 g of pure water were mixed, and this mixture was poured over 1 hour into the autoclave containing polymethylhydrosilazane A dissolved in pyridine and toluene. Dry nitrogen was poured in to replace the atmosphere inside the autoclave, and the contents were then filtered through a 5 μm Teflon (registered trademark) filter. The obtained filtrate was mixed with 100 g of toluene that had been dried with molecular sieves, and this was distilled in a rotary evaporator at a bath temperature of 50° C. until the contents became approximately 80 g. 100 g of dried toluene was mixed with this, and the solvent was thoroughly distilled off in a rotary evaporator also at a bath temperature of 50° C., yielding approximately 12 g of a viscous liquid.

[0057] The resulting viscous liquid was subjected to H-NMR (400 MHz) measurement using CDCl as a lock solvent. A peak at 0.1 to 0.2 ppm attributable to Si-Me bonds, a peak at 0.4 to 1.8 ppm attributable to N-H bonds, and a peak at 4.1 to 5.1 ppm attributable to Si-H bonds were observed. Based on the integral ratio of each peak (based on the number of protons), the ratio of Si-H bonds / Si-Me bonds was 0.63, and the ratio of N-H bonds / Si-Me bonds was 0.73.

[0058] Furthermore, when the viscous liquid was applied to a KBr plate and the FTIR spectrum was measured using an FTIR device (manufactured by Jasco: Model FT / IR-4100), a peak at 1,120 cm attributed to the Si—O bond was observed. －１ absorptions at 1,180 and 3,370 cm assigned to the N-H bond －１ absorption at 1,250 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ The absorption was observed.

[0059] Furthermore, when this viscous liquid was measured by GPC, it was found that the weight average molecular weight in terms of polystyrene was 11,500.

[0060] From the above analytical results, the obtained viscous liquid was identified as polymethylhydrosiloxazane.

[0061] [Synthesis of Polymethylsilazane] A 2-L stainless steel autoclave was equipped with a stirrer, nozzles for injecting and discharging chemicals or gases into the liquid and gas phases, and a cooling and control device for controlling the temperature of the contents. After thoroughly drying the autoclave with dry nitrogen, 300 g of toluene and 300 g of pyridine, which had been dehydrated with molecular sieves, were poured into the autoclave and cooled to 0°C with stirring. 25 g of dimethyldichlorosilane and 30 g of methyltrichlorosilane were gradually poured into the autoclave, and 50 g of dry ammonia was poured into the autoclave over 2 hours while maintaining the temperature at 0°C. After removing excess ammonia with dry nitrogen, the reaction solution was filtered through a SUS316 filter with a filtration accuracy of 25 μm. The resulting filtrate was mixed with 500 g of toluene dried with molecular sieves, and the mixture was distilled in a rotary evaporator at a bath temperature of 50°C until the contents reached approximately 200 g. This was mixed with 200 g of dried toluene, and the solvent was thoroughly distilled off using a rotary evaporator also at a bath temperature of 50° C., yielding about 20 g of a viscous liquid.

[0062] When the obtained viscous liquid was subjected to 1H-NMR (400 MHz) measurement using CDCl3 as a lock solvent, a peak at 0.1 to 0.2 ppm attributed to Si-Me bonds and a peak at 0.4 to 1.8 ppm attributed to N-H bonds were observed. Based on the integral ratio of each peak (based on the number of protons), the ratio of N-H bonds to Si-Me bonds was 1.22. Note that a peak at 4.1 to 5.1 ppm attributed to Si-H bonds was not observed.

[0063] The viscous liquid was applied to a KBr plate, and the FTIR spectrum was measured using an FTIR device (manufactured by Jasco: Model FT / IR-4100). The FTIR spectrum showed peaks at 1,180 and 3,370 cm assigned to the N—H bond. －１ absorption at 1,260 cm attributed to the Si-Me bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ The absorption of 2,160 cm attributed to the Si-H bond was observed. －１ No absorption was observed.

[0064] Furthermore, when this viscous liquid was measured by GPC, it was found that the weight average molecular weight in terms of polystyrene was 2,400.

[0065] From the above analysis results, the obtained viscous liquid was identified as polymethylsilazane.

[0066] [Synthesis of Hydrogenated Polysilazane] A 2-L stainless steel reactor equipped with a stirrer and a cooling device was thoroughly dried with dry nitrogen, and then 1,500 g of pyridine dried over molecular sieves was added and cooled to 0°C with stirring. 120 g of dichlorosilane was added over 1 hour to form a pyridine-dichlorosilane complex. Subsequently, 120 g of dry ammonia was added over 5 hours with stirring while maintaining the temperature at 0°C. After the reaction was completed, the slurry product was filtered under a dry nitrogen atmosphere using a SUS316 filter with a filtration accuracy of 25 μm to obtain 1,000 g of filtrate. This was then distilled under reduced pressure using a rotary evaporator with a bath temperature of 40°C to obtain 30 g of a viscous liquid.

[0067] The viscous liquid was applied to a KBr plate, and the FTIR spectrum was measured using an FTIR device (manufactured by Jasco: Model FT / IR-4100). This revealed peaks at 1,180 and 3,370 cm, which were attributed to N—H bonds. －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ absorption of 850 to 1,050 cm attributed to Si-H or Si-N bonds －１ The absorption at 1,260 cm attributed to the Si-Me bond was observed. －１ and 2,970 cm attributed to the C-H bond. －１ No absorption was observed.

[0068] Furthermore, when this viscous liquid was measured by GPC, it was found that the weight average molecular weight in terms of polystyrene was 1,500.

[0069] From the above analysis results, the obtained viscous liquid was identified as hydrogenated polysilazane.

[0070] Example 1 20 g of colloidal silica (organosilica sol MEK-ST-L manufactured by Nissan Chemical Industries, Ltd.: average particle size 45 nm, solid content concentration 30%) and 50 g of butyl acetate (A0024 manufactured by Tokyo Chemical Industry Co., Ltd.: purity >99%) were mixed and stirred in a 300 ml glass vessel, and 20 g of thoroughly dried molecular sieve 4A was added thereto. The vessel was left to stand at room temperature for one day for dehydration treatment. The mixture was then distilled in a rotary evaporator at a bath temperature of 50° C. until the content became approximately 30 g.

[0071] Subsequently, 100 g of dried butyl acetate was mixed, and the mixture was distilled in a rotary evaporator at the same bath temperature of 50° C. until the contents became 25 g. After allowing the mixture to cool to room temperature, 6 g of polymethylhydrosilazane A was mixed, stirred thoroughly, and filtered through a Teflon (registered trademark) membrane filter with a filtration accuracy of 1 μm to obtain a mixed dispersion of colloidal silica and polymethylhydrosilazane A. Note that under these conditions, the mixing ratio of colloidal silica (solid content) to polymethylhydrosilazane A was 100 wt %.

[0072] The mixed dispersion was dropped onto a silicon wafer with a diameter of 4 inches and spin-coated at 500 rpm for 30 seconds. The wafer was then left to stand on a hot plate heated to 300°C in the atmosphere for 10 minutes and then allowed to cool, forming a homogeneous thin film without cracks or peeling.

[0073] The silicon wafer with the film was cut, and the cross section was observed under SEM (magnification 10,000-80,000 times) using a JEOL Model JSM-IT800. As a result, the formation of a 2.1 μm thick film in which silica particles with diameters of 50-110 nm were distributed evenly was confirmed. Furthermore, the elemental composition of the film was measured by X-ray photoelectron spectroscopy (after the surface was sputtered) using a JEOL Photoelectron Spectrometer (ESCA). The carbon content (calculated as the amount of carbon atoms relative to the silica equivalent) was found to be 13.1 wt%. Furthermore, the FTIR spectrum of the film was measured using an FTIR device (Jasco Model FT / IR-4100) by subtracting the silicon wafer absorption as the background. As a result, the peaks at 470 and 980-1,270 cm attributable to Si-O bonds were observed. －１ absorption at 1,260 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ From this, the composition of the film was identified as methylhydrosiloxane.

[0074] Example 2 The same procedure as in Example 1 was carried out, except that polymethylhydrosilazane B was used instead of polymethylhydrosilazane A, to obtain a mixed dispersion of colloidal silica and polymethylhydrosilazane B. Under these conditions, the mixing ratio of colloidal silica (solid content) to polymethylhydrosilazane B was 100 wt %.

[0075] The mixed dispersion was dropped onto a silicon wafer with a diameter of 4 inches and spin-coated at 500 rpm for 30 seconds. The wafer was then left to stand on a hot plate heated to 300°C in the atmosphere for 10 minutes and then allowed to cool, forming a homogeneous thin film without cracks or peeling.

[0076] The silicon wafer with the film was cut, and the cross section was observed under SEM (magnification 10,000-80,000 times) using a JEOL Model JSM-IT800. As a result, the formation of a 2.3 μm thick film in which silica particles with a diameter of 40-100 nm were distributed evenly was confirmed. Furthermore, the elemental composition of the film was measured by X-ray photoelectron spectroscopy (after the surface was sputtered) using a JEOL photoelectron spectrometer (ESCA). The carbon content (calculated as the amount of carbon atoms relative to the silica equivalent) was found to be 16.8 wt%. Furthermore, the FTIR spectrum of the film was measured using an FTIR device (Jasco Model FT / IR-4100) by subtracting the silicon wafer absorption as the background. As a result, the peaks at 470 and 980-1,270 cm attributable to Si-O bonds were observed. －１ Absorption of 3,370 cm attributed to the N-H bond －１ absorption at 1,260 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ From this, the composition of the film was identified as methylhydrosiloxazane.

[0077] Example 3 A mixed dispersion of colloidal silica and polymethylhydrosiloxazane C was obtained by the same procedure as in Example 1, except that polymethylhydrosilazane C was used instead of polymethylhydrosilazane A. Note that under these conditions, the mixing ratio of colloidal silica (solid content) to polymethylhydrosiloxazane C was 100 wt %.

[0078] The mixed dispersion was dropped onto a silicon wafer with a diameter of 4 inches and spin-coated at 500 rpm for 30 seconds. The wafer was then left to stand on a hot plate heated to 300°C in the atmosphere for 10 minutes and then allowed to cool, forming a homogeneous thin film without cracks or peeling.

[0079] The silicon wafer with the film was cut, and the cross section was observed under SEM (magnification 10,000-80,000 times) using a JEOL Model JSM-IT800. As a result, the formation of a 2.1 μm thick film in which silica particles with a diameter of 40-110 nm were distributed evenly was confirmed. Furthermore, the elemental composition of the film was measured by X-ray photoelectron spectroscopy (after the surface was sputtered) using a JEOL Photoelectron Spectrometer (ESCA). The carbon content (calculated as the amount of carbon atoms relative to the silica equivalent) was found to be 10.8 wt%. Furthermore, the FTIR spectrum of the film was measured using an FTIR device (Jasco Model FT / IR-4100) by subtracting the silicon wafer absorption as the background. As a result, the peaks at 470 and 980-1,270 cm attributable to Si-O bonds were observed. －１ absorption at 1,260 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ From this, the composition of the film was identified as methylhydrosiloxane.

[0080] Example 4 A mixed dispersion of colloidal silica and polymethylhydrosilazane A was obtained by the same procedure as in Example 1, except that 20 g of colloidal silica (organosilica sol MEK-ST manufactured by Nissan Chemical Industries, Ltd.: average particle size 12 nm, solid content 30%) was used instead of 20 g of colloidal silica (organosilica sol MEK-ST manufactured by Nissan Chemical Industries, Ltd.: average particle size 45 nm, solid content 30%). Note that under these conditions, the mixing ratio of colloidal silica (solid content) to polymethylhydrosilazane A was 100 wt %.

[0081] The mixed dispersion was dropped onto a silicon wafer having a diameter of 4 inches and spin-coated at 500 rpm for 30 seconds. The wafer was then placed on a hot plate heated to 300°C in the atmosphere for 10 minutes and allowed to cool, forming a homogeneous thin film without cracks or peeling.

[0082] The silicon wafer with the film was cut, and the cross section was observed under SEM (magnification 10,000-80,000 times) using a JEOL Model JSM-IT800. As a result, the formation of a 1.8 μm thick film in which silica particles with a diameter of 7-20 nm were distributed evenly was confirmed. Furthermore, the elemental composition of the film was measured by X-ray photoelectron spectroscopy (after the surface was sputtered) using a JEOL Photoelectron Spectrometer (ESCA). The carbon content (calculated as the amount of carbon atoms relative to the silica equivalent) was found to be 12.2 wt%. Furthermore, the FTIR spectrum of the film was measured using an FTIR device (Jasco Model FT / IR-4100) by subtracting the silicon wafer absorption as the background. As a result, the peaks at 470 and 980-1,270 cm attributable to Si-O bonds were observed. －１ absorption at 1,260 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ From this, the composition of the film was identified as methylhydrosiloxane.

[0083] Example 5 A mixed dispersion of colloidal silica and polymethylhydrosilazane A was obtained by the same procedure as in Example 1, except that the amount of colloidal silica (organosilica sol MEK-ST-L manufactured by Nissan Chemical Industries, Ltd.: average particle size 45 nm, solid content concentration 30%) was changed to 2 g and the amount of polymethylhydrosilazane A mixed was changed to 12 g. Note that under these conditions, the mixing ratio of colloidal silica (solid content) to polymethylhydrosilazane A was 5.0 wt %.

[0084] The mixed dispersion was dropped onto a silicon wafer having a diameter of 4 inches and spin-coated at 500 rpm for 30 seconds. The wafer was then placed on a hot plate heated to 300°C in the atmosphere for 10 minutes and allowed to cool, forming a homogeneous thin film without cracks or peeling.

[0085] The silicon wafer with the film was cut, and the cross section was observed (magnification 10,000-80,000 times) using a JEOL Model JSM-IT800 for SEM observation. As a result, the formation of a 1.5 μm thick film in which silica particles with diameters of 40-110 nm were distributed sparsely but evenly was confirmed. Furthermore, the elemental composition of the film was measured by X-ray photoelectron spectroscopy (after the surface was sputtered) using a JEOL photoelectron spectrometer (ESCA). The carbon content (calculated as the amount of carbon atoms relative to the silica equivalent) was found to be 17.8 wt%. Furthermore, the FTIR spectrum of the film was measured using an FTIR device (Jasco Model FT / IR-4100) by subtracting the silicon wafer absorption as the background. The results showed that the peaks at 470 and 980-1,270 cm attributable to Si—O bonds were observed. －１ Absorption of 3,370 cm attributed to the N-H bond －１ absorption at 1,260 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ From this, the composition of the film was identified as methylhydrosiloxazane.

[0086] Example 6 A mixed dispersion of colloidal silica and polymethylhydrosilazane A was obtained by the same procedure as in Example 1, except that the amount of colloidal silica (organosilica sol MEK-ST-L manufactured by Nissan Chemical Industries, Ltd.: average particle size 45 nm, solid content 30%) was changed to 25 g and the amount of polymethylhydrosilazane A mixed was changed to 4 g. Under these conditions, the mixing ratio of colloidal silica (solid content) to polymethylhydrosilazane A was 187.5 wt %.

[0087] The mixed dispersion was dropped onto a silicon wafer having a diameter of 4 inches and spin-coated at 500 rpm for 30 seconds. The wafer was then placed on a hot plate heated to 300°C in the atmosphere for 10 minutes and allowed to cool, forming a homogeneous thin film without cracks or peeling.

[0088] The silicon wafer with the film was cut, and the cross section was observed under SEM (magnification 10,000-80,000 times) using a JEOL Model JSM-IT800. As a result, the formation of a 1.9 μm thick film in which silica particles with diameters of 50-110 nm were distributed evenly was confirmed. Furthermore, the elemental composition of the film was measured by X-ray photoelectron spectroscopy (after the surface was sputtered) using a JEOL photoelectron spectrometer (ESCA). The carbon content (calculated as the amount of carbon atoms relative to the silica equivalent) was found to be 8.1 wt%. Furthermore, the FTIR spectrum of the film was measured using an FTIR device (Jasco Model FT / IR-4100) by subtracting the silicon wafer absorption as the background. As a result, the peaks at 470 and 980-1,270 cm attributable to Si-O bonds were observed. －１ absorption at 1,260 cm attributed to the Si-Me bond －１ absorption at 2,160 cm, which is attributed to the Si-H bond －１ Absorption at 2,970 cm attributed to the C-H bond －１ From this, the composition of the film was identified as methylhydrosiloxane.

[0089] Example 7 The mixed dispersion of colloidal silica and polymethylhydrosilazane B shown in Example 2 was dropped onto a silicon wafer on which linear grooves 40 μm wide and 30 μm deep at their deepest point had been formed, and the wafer was spin-coated at 500 rpm for 30 seconds. The wafer was then held on a hot plate heated to 300° C. in the atmosphere for 10 minutes and then allowed to cool, forming a thin film free of cracks and peeling.

[0090] The silicon wafer with the film was cut, and the cross section of the linear groove portion was observed under SEM (magnification 10,000 to 80,000 times) using a JEOL model JSM-IT800. The film thickness (H2) at the center of the groove width was 12.5 μm, and the film thickness outside the groove (portion 2 mm away from the groove end) was 2.2 μm, and it was confirmed that the thin film had silica fine particles with diameters of 50 to 110 nm distributed evenly both inside and outside the groove. Furthermore, no cracks or peeling were observed even in the SEM observation.

[0091] Comparative Example 1 A mixed dispersion of colloidal silica and polymethylsilazane was obtained by the same procedure as in Example 2, except that polymethylsilazane was used instead of polymethylhydrosilazane B. The obtained mixed dispersion was dropped onto a silicon wafer on which linear grooves 40 μm wide and 30 μm deep at their deepest point had been formed, and spin-coated at 500 rpm for 30 seconds. This was then held on a hot plate heated to 300° C. in the atmosphere for 10 minutes and then allowed to cool, forming a thin film.

[0092] Visual observation of the formed thin film confirmed peeling and cracks originating from the grooves. The silicon wafer with the film was cut, and the cross section of the linear grooves was observed under SEM (magnification 10,000-80,000x) using a JEOL JSM-IT800. Peeling of the film from the substrate was observed inside the grooves, making it impossible to measure the film thickness. The film thickness outside the grooves where no peeling occurred (2 mm away from the groove end) was 1.9 μm. A thin film with an even distribution of particles with diameters of 50-110 nm was also confirmed outside the grooves.

[0093] Comparative Example 2 A mixed dispersion of colloidal silica and hydrogenated polysilazane was obtained by the same procedure as in Example 2, except that hydrogenated polysilazane was used instead of polymethylhydrosilazane B. The mixed dispersion obtained was dropped onto a silicon wafer on which linear grooves 40 μm wide and 30 μm deep at their deepest point had been formed, and spin-coated at 500 rpm for 30 seconds. This was then held on a hot plate heated to 300° C. in the atmosphere for 10 minutes and then allowed to cool, forming a thin film.

[0094] Visual observation of the formed thin film confirmed numerous peelings and cracks over the entire surface of the substrate. This silicon wafer with the thin film was cut, and the cross section of the linear groove portion was observed under SEM (magnification 10,000 to 80,000 times) using a JEOL Model JSM-IT800. Peeling of the film from the substrate was observed both inside and outside the groove, making it impossible to measure the film thickness.

[0095] [Configurations of the Invention] [Configuration 1] A substrate comprising a film in which silica fine particles are dispersed in a matrix material of a methylhydrosiloxane composition or a methylhydrosiloxazane composition. [Configuration 2] The substrate according to Configuration 1, wherein the substrate has a step of 1 μm or more, and the film is embedded 1 μm or more from the bottom of the step. [Configuration 3] The substrate according to Configuration 1 or 2, wherein the film has an average carbon content of 8 wt % to 18 wt %. [Configuration 4] The substrate according to any one of Configurations 1 to 3, wherein the silica fine particles have an average primary particle size of 5 nm to 150 nm. [Configuration 5] A method for manufacturing a substrate, comprising applying to a substrate and heating a material in which silica fine particles are dispersed in a matrix material of polymethylhydrosilazane or polymethylhydrosiloxazane having a weight-average molecular weight of 400 to 20,000. [Structure 6] The method for manufacturing a substrate according to Structure 5, wherein the silica fine particles have an average primary particle size of 5 nm or more and 150 nm or less. [Structure 7] The method for manufacturing a substrate according to Structure 5 or 6, wherein a mixing ratio (weight ratio) of the silica fine particles to the matrix material is 3 wt % or more and 200 wt % or less. [Structure 8] The method for manufacturing a substrate according to any one of Structures 5 to 7, wherein a ratio of Si—H bonds / Si—Me bonds in the structure of the matrix material is 0.3 or more and 0.9 or less, and a ratio of N—H bonds / Si—Me bonds is 0.4 or more and 1.1 or less.

[0096] 10 substrate, 12 film, 100 film-attached substrate.

Claims

1. A substrate comprising a film having silica fine particles dispersed in a matrix material of a methylhydrosiloxane composition or a methylhydrosiloxazane composition.

2. A substrate according to claim 1, characterized in that said substrate has a step of 1 μm or more, and said film is embedded at a depth of 1 μm or more from the bottom of said step.

3. A substrate according to claim 1 or 2, characterized in that the average carbon content of said film is between 8 wt % and 18 wt %.

4. A substrate according to any one of claims 1 to 3, wherein the silica fine particles have an average primary particle size of 5 nm or more and 150 nm or less.

5. A method for manufacturing a substrate, comprising applying to a substrate a material in which silica fine particles are dispersed in a matrix material of polymethylhydrosilazane or polymethylhydrosiloxazane having a weight average molecular weight of 400 or more and 20,000 or less, and heating the matrix material.

6. A method for manufacturing a substrate according to claim 5, wherein the silica fine particles have an average primary particle size of 5 nm or more and 150 nm or less.

7. A method for manufacturing a substrate according to claim 5 or 6, characterized in that the mixing ratio (weight ratio) of said silica fine particles to said matrix material is 3 wt % or more and 200 wt % or less.

8. A method for manufacturing a substrate according to claim 5 or 6, characterized in that the ratio of Si-H bonds / Si-Me bonds in the structure of the matrix material is 0.3 or more and 0.9 or less, and the ratio of N-H bonds / Si-Me bonds is 0.4 or more and 1.1 or less.

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